Inversion therapy is a method for achieving a decompression of the musculoskeletal system. Spinal traction occurs when the head is at a lower plane of elevation than the feet, thereby reversing the normal gravitational loading which occurs while standing or sitting.
The degree of traction is measured by the angular displacement of the head from the horizontal plane which exists while lying flat in a prone position. The range of traction is therefore zero to ninety degrees, with maximum traction occurring while suspended orthogonal to the level surface below.
Gravity boots are an established method for enabling an inverted posture through ankle-based suspension. Traditional gravity boot designs use hooks which connect to an elevated horizontal bar. This requires attaching a pair of gravity boots to the ankles, and then raising the feet to the elevation of the bar to enter the inverted posture.